Control Device for Fluid Loading and/or Unloading System

ABSTRACT

1. A marine loading arm which includes at least one fluid transfer line having a fixed line end fixed to a base and a moveable line end provided with a coupling adapted for connection to a target duct. The coupling has at least three degrees of freedom relative to the base and the marine loading arm further includes a control device for controlling the movement and positioning of the coupling. The control device has at least three actuators, each of which controls movement of the coupling in a corresponding degree of freedom and each of which comprises an electric motor which is provided at an articulation of the loading arm providing one of the degrees of freedom. The control device further includes a first global positioning system device positioned on or adjacent the coupling for providing information on the absolute positioning of the coupling in space.

This application is a continuation of U.S. patent application Ser. No.12/736,789 filed on Nov. 8, 2010, which is based on International PatentApplication No. PCT/IB2008/002685 filed on Jun. 23, 2008.

BACKGROUND OF THE INVENTION

The present invention generally relates to systems for loading and/orunloading fluids for ships, commonly referred to as marine loadingsystems. These systems are used to transfer a fluid product between aship and a quay or between two ships.

Fluid product is understood to mean a liquid or gaseous product. Moreparticularly, the present invention concerns the devices for controllingmovement, positioning and connection of such loading and/or unloadingsystems.

Generally, marine loading systems have a fluid transfer line end that isfixed to a base and connected to a tank of fluid to be transferred, andan opposite line end that is moveable and provided with a couplingadapted for connecting to a target duct, which itself connected to afluid tank.

Two families of fluid loading systems for ships are known, which aredistinguished by their structure: systems for transfer by rigid pipesand systems for transfer by flexible pipes.

In the family of systems for transfer by rigid pipes, loading armsystems and pantograph systems can be distinguished.

The loading arm is an articulated tubing arrangement, comprising a base,connected to fluid tank, on which there is mounted a first pipe,designated inner pipe, via a portion of tube with a 90° bend enablingrotation of one of its ends about a vertical axis, and the other endabout a horizontal axis. At the opposite end of the inner tube, a secondpipe, designated outer pipe, is rotatably mounted about a horizontalaxis. A coupling is mounted at the end of the outer pipe. Each of thethree rotations is controlled by a jack or hydraulic motor.

The pantograph systems, like the loading arms, comprise a base connectedto a tank. A crane is rotatably mounted on that base. The cranecomprises a boom carrying a pipe for the fluid. At the end of the boomthere is mounted a pantograph composed of articulated pipes for thefluid, and enabling a coupling to be moved that is mounted at the freeend of the pantograph. The inclination of the pantograph is controlledby a rotation at the end of the boom. The movement of the pantograph iscontrolled by hydraulic motors and by a jack for the rotation on thebase.

Lastly, the flexible piping systems generally comprise a line in whichis conveyed the fluid product and a mechanical system enabling the lineto be maneuvered. There are several types of maneuvering systems, but inall cases they include a manipulating crane or structure which supportsthe coupling for connecting the flexible piping.

In general, the loading system comprises an actuator at its end enablingthe coupling to be clamped or unclamped. In general, this is one or morejacks or one or more hydraulic motors.

In practice, in most systems, the coupling is articulated at its endwith three degrees of rotational freedom. In this way an angularorientation of the plane of the coupling relative to the plane of thetarget duct is possible independently of the inclination of the arm, theplane of the coupling remains parallel to the plane of the target ducton approach for the connection, and then, once the coupling has beenclamped onto the target duct, these articulations enable a “floating”movement of the assembly. In practice, the rotations are controlled bythe operator via hydraulic motors or jacks until connection of thecoupling to the target duct has been achieved. Once the coupling hasbeen clamped the hydraulic motors or jacks are disengaged or “set tofreewheel” to enable the loading system to follow the movements of thetarget duct without constraining the coupling.

The two families of loading devices described above have structuraldifferences, but their control systems are designed according to thesame general principle of operation. It is noted that, in all cases, thecoupling has at least three degrees of freedom relative to the basebearing the fixed end of the duct, and that the movements in each ofthese degrees of freedom are independently controlled by actuators. Theoperator has a command interface enabling him to control the movement ofthe coupling.

Each actuator is controlled either separately by an independent controlof the on/off type, or by a simultaneous proportional control. In thecase of on/off independent controls, the operator can act independentlyon each of the controls to control a particular member of the loadingsystem. The combined action on the group of actuators enables thecoupling to be positioned at a desired point in space.

In the case of proportional controls, the operator has a command inputinterface comprising a proportional control cooperating with acalculator such that acting on said proportional control with higher orlower magnitude leads to at least one proportional control instructionthat is respectively of higher or lower magnitude for the correspondingactuators, resulting in a movement of the coupling at a speed ofmovement that is respectively higher or lower.

The operator may thus directly control the movement of the coupling, andmay thus in particular achieve movement of the coupling that isrectilinear, and/or at constant speed, since the calculator composes themovement of the coupling by acting on all the actuators simultaneously.

In general, the actuators used are hydraulic, for example a hydraulicmotor or jack, but the use of electric actuators is also known, forexample electric motors, or pneumatic actuators. The actuators equippingmarine loading systems are controlled either by an on/off control, witha constant speed of movement, and in certain cases, with the possibilityof setting two speeds of movement at will for the independent controlsof the on/off type, or by proportional distributors, in the case ofproportional controls.

In all cases, the connection of the coupling to the target duct is mademanually, the operator thus maneuvers the loading system, with orwithout the intermediary of a control calculator in order to come toconnect the coupling on the target duct.

These control devices are difficult to implement, in that the operatormust know the functioning and kinematics of the marine loading systemperfectly. Furthermore, he must compensate for the movements of theship, in particular in the case of rough sea. This increases the risk ofthe coupling striking against obstacles or against the target duct,which may damage the seals of the coupling. The maneuvering and theconnection thus require qualified personnel.

A system is known making it possible to facilitate the connection of acoupling to a target duct in which the coupling is linked in advance bya cable to the target duct. A cable is thrown between the quay or theship bearing the base and the ship bearing the target duct, thenattached by operators between the target duct and the base. A winch thenenables the arm to be advanced along the tensioned cable and thus thecoupling to be drawn towards the target duct. This system is commonlycalled a “targeting system”. It is a semi-automatic system: once thecable has been connected, an operator must control the movement of thecoupling along the cable by actuating the winding operation. A guidingcone is provided for the final phase of the approach. Once the couplinghas been brought near, an operator must finalize its connection and itsclosure manually.

This mode of semi-automatic connection requires experienced staff and asuitable heavy mechanical structure (in particular a motor adapted todraw the arm along the cable, an anchorage point for the opposite end ofthe cable, and a guiding cone for the approach in the final phase).

On the basis of these observations, the invention aims to provide adevice for facilitating the operation of controlling movement of thecoupling for the operator, in particular to make it possible to succeedin connecting the coupling in unfavorable sea conditions, and moregenerally to facilitate the connection and make it more rapid in allcases, while reducing the risk of striking of the coupling.

SUMMARY OF THE INVENTION

To that end the invention provides a control device for the movement andpositioning of a coupling for a marine loading system, said marineloading system comprising at least one fluid transfer line having a lineend fixed to a base and a moveable line end provided with a couplingadapted for connection to a target duct, the coupling having at leastthree degrees of freedom relative to the base, the device beingcharacterized in that it comprises at least three actuators, each forcontrolling the movement of the system in a corresponding degree offreedom, and at least one of the coupling and the target duct, or amember immediately neighboring the at least one of the coupling and thetarget duct, comprises at least one means for providing information onpositioning of the coupling, and the device furthermore comprisescalculating means adapted to:

calculate the relative positioning of the coupling directly relative tothe target duct according to the information provided by the positioninginformation means of the coupling;

calculate control instructions to give to each of the actuators suchthat their combined movements result in a movement of the coupling aimedat bringing the coupling closer to the target duct;

apply said control instructions to bring the coupling closer to thetarget duct; and

repeat the three preceding steps until the coupling is presented infront of the target duct in a position for connection.

Immediately neighboring members is understood to mean members of themarine loading system which are fixed or moveable relative to thecoupling or the target duct respectively, but sufficiently close theretowhatever the geometric configuration of the loading system, to giveprecise information as to the relative positioning of the couplingrelative to the target duct, in particular to make it possible toprecisely present the coupling automatically in front of the target ductfor the purpose of connection.

Advantageously, the device according to the invention enables theoperator to dispense with controlling the movement of the couplingduring the approach of the target duct for connection, since the devicetakes on the task of controlling the movement of the couplingautomatically until the latter is presented in front of the target duct.

In other words, the device according to the invention enables thecoupling to be automatically moved until it is located in front of thetarget duct in position for connection. The operator no longer needs tocontrol the movement of the coupling for connection to the target duct;the movement of the coupling into position for connection is madeautomatically.

This advantageously makes it possible to facilitate the connection andmake it faster in all cases and more particularly to succeed in makingthe connection of the coupling in unfavorable sea conditions, whilereducing the risk of striking of the coupling.

With the device according to the invention, the connection is possibleeven for a novice operator.

The device according to the invention enables the safety of use to beincreased by eliminating any risk of improper manipulation.

Advantageously, the invention adapts to any type of marine loadingsystem, to the systems for transfer by rigid pipes as well as to thesystems for transfer by flexible pipes, since the means for providinginformation on positioning of the coupling enable information to beobtained on the relative positioning of the coupling directly relativeto the target duct independently of the kinematics and the structure ofthe loading system.

According to advantageous features, which may be combined:

at least one of the coupling and the target duct, or a member that isfixed relative to the at least one of the coupling and the target duct,comprises at least one means for providing information on positioning ofthe target duct, and the calculating means are adapted to deduce on thebasis of the information on positioning of the target duct and of theinformation on positioning of the coupling provided by the at least twomeans for providing positioning information, the relative position ofthe coupling relative to the target duct;

the means for providing information on the positioning of the couplingand the means for providing information on the positioning of the targetduct are designed to communicate with each other, and comprisecalculating means for calculating and directly providing information onrelative positioning of the coupling relative to the target duct; and

the coupling is articulated at its end with three degrees of rotationalfreedom and at least one of the three rotations is controlled by anactuator, the device being provided with means for providing informationon the angular orientation of the coupling and means for providinginformation on the angular orientation of the target duct, thecalculating means being adapted to calculate, on the basis of theinformation provided by the means for providing information on theangular orientation, control instructions to give to the at least oneactuator in order for the angular orientation of the coupling, inposition for connection, to be substantially the same as the angularorientation of the target duct.

Advantageously, the coupling is orientated along the same axis as thetarget duct which enables a precise and reliable connection, whilelimiting the risk of collision and of deterioration of the seals.

In accordance with advantageous features of the invention, which may becombined:

the device further comprises an actuator enabling the coupling to beclamped and unclamped, and, once the coupling has been presented infront of the target duct in a position for connection, the calculatingmeans apply a control instruction to said actuator to clamp the couplingonto the target duct; and

once the coupling has been connected and clamped onto the target duct,the calculating means apply an instruction to disengage the actuators tocontrol the movement of the system in its degrees of freedom, so as tomake the movements of the system free.

Thus, advantageously, the connection is made without human intervention,even if the target duct moves, for example when the sea is rough. Theclamping of the coupling is automatic once it has been presented in theposition for connection. The actuators of the loading system are thenallowed to be free in their movements to enable the coupling and theloading system to follow the movements of the target duct withoutdamaging the loading system.

According to advantageous features, which may be combined:

the means for providing information on the positioning of the targetduct includes a device of a system for global positioning, in particularof GPS type, making it possible to give an absolute position of thetarget duct, the calculating means being adapted to calculate, on thebasis of the information on absolute positioning of the target duct, therelative positioning of the coupling relative to the target duct;

the means for providing information on the positioning of the couplingincludes a device of a system for global positioning, in particular ofGPS type, making it possible to give an absolute position of thecoupling, the calculating means being adapted to calculate, on the basisof the information on absolute positioning of the coupling and of thetarget duct, the relative positioning of the coupling relative to thetarget duct;

the devices for global positioning, in particular of GPS type, aredevices designed to communicate with each other and comprise calculatingmeans for calculating and providing directly information on relativepositioning of the coupling relative to the target duct;

one of the means for providing information on positioning of thecoupling or of the target duct includes an optical device, adapted tocooperate with the target duct or the coupling respectively or a targetthat is fixed relative to the target duct or relative to the couplingrespectively, by emitting a luminous beam, such as a laser beam, towardsthe target duct or the coupling or a target that is fixed relative tothe target duct or the coupling respectively, and to detect thereflected beam and to measure the travel time of the beam to deducetherefrom information on relative positioning of the coupling directlyrelative to the target duct;

the means for providing information on positioning of the couplingincludes an optical camera, designed and mounted to provide an image ofthe coupling to the calculating means, the calculating means beingadapted to process the image provided by the camera to calculate therelative positioning of the coupling relative to the target duct;

at least one cord is tensioned using a reel between the coupling and thetarget duct and the means for providing information on positioning areat least one angle sensor and/or at least one unwound cord length sensoron the reel, chosen so as to provide the calculating means withinformation making it possible to calculate the relative positioning ofthe coupling relative to the target duct;

at least one of the actuators for controlling the movement of the systemin a degree of freedom is a proportional control actuator;

the device comprises a command interface for an operator, and thecommunication between the command interface and the calculating means isperformed wirelessly, the command interface comprising a transmitter forwireless communication with a receiver linked to the calculating means;and

the device comprises at least two means for providing information onpositioning of the coupling, one making it possible to determine thepositioning of the coupling with greater precision than the other andthe calculating means using, for the positioning of the coupling, thepositioning means having greater precision when the distance between thecoupling and the target duct becomes less than a predefined distance.

When the coupling is moved too far from the base, there is a risk ofdamage to the system, in particular by rupture or interference. When thecoupling is moved too far from the base during extension there is a riskof rupture of the system. When the coupling is rotated relative to thebase, in particular when several loading systems are disposed inparallel on a quay, there is a risk of collision with the neighboringloading systems: the term damage by interference is used.

To avoid such damage to the loading system, alarm devices have beenprovided on certain types of loading devices.

Systems are known using proximity detectors and angle sensors disposedon the members or on the path of members of the loading system. Thesystems for detecting proximity or switches have the drawback ofrequiring knowledge of the kinematics of the loading system andconsequently the requirement to position switches or sensors on thesystem for defining working zones. Furthermore, these sensors only givea signal of the on/off type, which limits the possibilities for alarms.There is a single zone limit per sensor. The devices with angle sensorsenable working zones to be defined, but impose a system with a rigidstructure for placing the sensors therein. Lastly, no systems are knownat present enabling alarms to be triggered for the systems with flexiblepiping.

To that end, according to an advantageous feature of the presentinvention, the at least one means for providing information onpositioning of the coupling is either adapted to cooperate directly witha means for providing information on positioning of the base disposed onthe base or on a member that is fixed relative to the base to provide,on the basis of the information on positioning of the base, informationon relative positioning of the coupling directly relative to the base,or adapted to provide information on absolute positioning of thecoupling in space, and, the base having a fixed position in space, thedevice comprises a calculating means making it possible to calculate onthe basis of the information on absolute positioning of the coupling anddata on positioning of the base fixed in space, information on relativepositioning of the coupling directly relative to the base, the devicefurther comprises calculating means adapted to:

calculate, in real time, according to the movements of the couplingrelative to the base and the information on positioning of the couplingrelative to the base, data defining at least one positioning zoneauthorized for the coupling being parameterized in the calculatingmeans;

check, in real-time, whether the coupling is located within theauthorized zone; and

emit a specific alarm when the coupling leaves the correspondingauthorized zone to warn the operator.

Thus, authorized zones or working zones are defined virtually by thecalculating means. It is not necessary to provide sensors or switchesphysically disposed on the loading system to define such zones and theyare easy to parameterize via the calculating means.

This makes it possible to increase the safety of use by virtue of alarmstriggered more precisely, independently of the kinematics and of thestructure of the loading system.

Furthermore, it is possible to provide a plurality of authorized zones,for example overlapping one within the other, having different degreesof working risk, and corresponding to different alarms according towhether the work in the zone concerned bears a greater or lesser risk.

According to an advantageous feature, the calculating means are adaptedto stop the application of the control instructions to give to each ofthe actuators for imparting movement to the coupling.

Thus, the connection procedure is automatically stopped when an alarmhas been triggered, which enables the device according to the inventionto be made safer.

According to an advantageous feature, several marine loading systems areconnected to the calculating means, and a selector is provided at thecommand interface to selectively control one of the loading systemsconnected to the calculating means.

Thus the operator just has to select the arm of which he wishes toconnect the coupling, and the operation will be performed automatically,whether the target duct is mobile or static.

According to another aspect, the invention provides a calculator for adevice as described above that is adapted to:

calculate the relative positioning of the coupling relative to thetarget duct according to the information provided by the means forproviding information on positioning of the coupling;

calculate control instructions to give to each of the actuators suchthat their combined movements result in a movement of the coupling aimedat bringing the coupling closer to the target duct; and

apply said control instructions to bring the coupling closer to thetarget duct until it is presented in front of the target duct in aposition for connection.

According to another aspect, the invention provides a method for thecalculating means of a device as described above comprising thefollowing calculating steps:

calculating the relative positioning of the coupling relative to thetarget duct according to the information provided by the means forproviding information on positioning of the coupling;

calculating control instructions to give to each of the actuators suchthat their combined movements result in a movement of the coupling aimedat bringing the coupling closer to the target duct; and

applying said control instructions to bring the coupling closer to thetarget duct until it is presented in front of the target duct in aposition for connection.

The explanation of the invention will now be continued with the detaileddescription of an embodiment, given below by way of non-limitingexample, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view in perspective of a loading arm equippedwith a control device according to the invention;

FIG. 2 is an synoptic diagram of the operation of the device accordingto FIG. 1;

FIG. 3 is a function diagram to represent the principle of operation ofthe control device according to FIGS. 1 and 2;

FIG. 4 is a diagrammatic view in perspective of another embodiment of aloading arm equipped with a control device according to the invention;

FIG. 5 is a diagrammatic view in perspective of another embodiment of aloading arm equipped with a control device according to the invention;and

FIGS. 6a and 6b are diagrammatic views in perspective of anotherembodiment of the loading arm equipped with a control device accordingto the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a very diagrammatic representation of a loading arm 2 equippedwith a control device 1 according to the invention. The representationof the loading arm here is very simplified, and it should be recalled inthis connection that the control device according to the inventionadapts to any type of marine loading system, in particular to theloading systems described above.

The loading arm of FIG. 1 comprises a base 21 connected to a fluid tankwhich is located below the surface 22 on which the base is fixed. In thepresent case it is a quay, but in a variant it is a ship. At the apex ofthe base there is rotatably articulated a bent tube 23, on which isarticulated in turn a first tube referred to as an inner tube 24 whichis articulated at its opposite end with a second tube referred to as anouter tube 25. The end of the outer tube carries a coupling 26 adaptedto be connected to a target duct 35, disposed in the present example ona ship 36 represented very diagrammatically.

In the embodiment represented, in a manner known per se, the couplinghas three degrees of freedom in rotation relative to the end of theouter tube. In the present embodiment, these three rotations are free,such that an operator may freely adjust the angle of the coupling duringthe final phase of approach for the connection of the coupling to thetarget pipe.

In an alternative embodiment, not shown, one or more of these rotationsare controlled by actuators and connected to a command interface toenable the operator directly to control the rotations on the finalapproach of the coupling.

In a manner known per se, the coupling in the present embodiment haslocking claws 31 which are closed by an actuator 30 represented verydiagrammatically to hold the coupling 26 around the target duct 35, oncethey are connected.

Generally, this type of loading arm is known per se, and will not bedescribed in more detail here. It will moreover be recalled that thecontrol device according to the invention adapts to all the marineloading systems, and that the adaptation of the control device accordingto the invention to any other type of loading system, in particular oneof the systems described above, is within the capability of the personskilled in the art.

In the device according to the invention as represented diagrammaticallyin FIG. 1, actuators 27, 28, 29 are provided at each of the threearticulations of the loading arm (symbolized by the double arrows A, B,C). More specifically, a first actuator 27 is provided between the apexof the base 21 and the bent tube 23, to pivot the latter horizontallyrelative to the base, a second actuator 28 is provided between the endof the bent tube 23 and the inner tube 24 so as to pivot the inner tubevertically, and a third actuator 29 is provided between the inner tube24 and the outer tube 25 to make the latter pivot vertically.

The three actuators 27, 28, 29 are hydraulic jacks here represented verydiagrammatically in FIG. 1. In a variant not illustrated, one or more ofthe hydraulic jacks are replaced by hydraulic motors. According toanother variant not illustrated, the actuators are electric or pneumaticmotors.

The target duct 35 provided here on a ship 36 represented verydiagrammatically is provided with a box 34 enclosing a means forproviding information on positioning of the target duct which is, in thepresent embodiment, a device of a system for global positioning of theGPS type, enabling an absolute position to be given, and moreparticularly the spatial coordinates of the free end of the target duct.

The same applies for the coupling 26, which comprises a box 33 enclosinga device of a system for global positioning of the GPS type, enabling anabsolute position to be given, and more particularly the spatialcoordinates of the connecting end of the coupling.

The calculating means of the control device are combined into acalculator 41 disposed in an electrical control cabinet 40.

A hydraulic power unit 42 is provided to supply the actuators with thehydraulic energy necessary for their operation. It is controlled by thecalculator 41.

The GPS boxes 33 and 34 are each respectively provided with an emittingdevice 33A and 34A to emit a signal comprising positioning information.The calculator 41 is linked to a receiver device 40A adapted to receivesaid signals from the emitters 33A and 34A. The control devicefurthermore comprises a command interface 60 for an operator.

Alternatively, the box 33 is positioned on a member immediatelyneighboring the coupling, for example one of the members articulated tothe end of the arm, the calculating means being adapted to extrapolatethe information on positioning of the coupling relative to theinformation provided by the box.

As can be seen more particularly in FIG. 2, in the synoptic diagram ofthe operation of the device according to FIG. 1, the calculator 41 islinked to the receiver device 40A, which is a radio receiver adapted tocommunicate with the radio transmitter devices 33A and 34A respectivelylinked to the GPS boxes 33 and 34 of the coupling and of the targetduct. The GPS boxes thus provide the calculator with information on thepositioning of the coupling and of the target duct.

In an alternative embodiment, the GPS boxes are devices designed tocommunicate with each other so as to directly provide information on therelative position of the coupling relative to the target duct, to thecalculator.

The loading arm 2 is equipped with actuators 27, 28, 29, which arecontrolled by valves that are themselves controlled by the calculator.The hydraulic power unit 42 supplies the actuators via said valves withthe hydraulic energy necessary for their operation. The hydraulic powerunit 42 is controlled by the calculator via power relay 43 to controlthe starting and stopping of the hydraulic power unit. The hydraulicpower unit comprises a pump (not represented) adapted to pump ahydraulic fluid to supply the actuators.

The command interface 60 is linked to the calculator to enable anoperator to command the connection of the coupling to the target duct.

As can be seen in FIGS. 2 and 3, when the operator wishes to connect thecoupling to the target duct, he actuates a button 61 on the commandinterface 60 to order the connection. A signal corresponding to hisorder is then sent to the calculator. The calculator then launches theautomatic connection procedure.

The calculator receives, via the radio receiver 40A, the information onpositioning of the coupling and of the target duct from the respectiveGPS boxes 33 and 34. Alternatively, in another embodiment, thecalculator receives the information by cable directly from the GPSboxes. According to an alternative embodiment, the GPS box 34 situatedon the ship sends the information on positioning of the target duct tothe GPS box 33 of the loading arm which calculates the relativepositioning of the coupling relative to the target duct and sends backthe result to the calculator by radio or wire link.

The calculator converts this information into spatial coordinates toobtain the relative position of the coupling relative to the targetduct.

On the basis of the information on the relative position of the couplingrelative to the target duct, the calculator calculates the distancesthat remain between the coupling and the target duct along the X, Y andZ axes, which are diagrammatically represented in FIG. 1.

If these three distances are not zero, or equal to distancesparameterized as reference distances that are known for the connection,the calculator calculates control instructions for each of the actuators27, 28, 29 of the arm such that their combined movements result in amovement of the coupling aimed at bringing the coupling closer to thetarget duct along the three axes. The calculator then applies thecontrol instructions calculated for each actuator to the actuators 27,28, 29 via the corresponding valves. Once the instructions have beenexecuted by the actuators, the calculator again calculates the distancesremaining between the coupling and the target duct along the X, Y and Zaxes. If these distances are not still zero or equal to theparameterized distances (for example, when the sea conditions are bad)the calculator recommences the calculations of the instructions for theactuators and applies them until the distances are zero or equal to theparameterized distances. In other words, the calculator applies controlinstructions, at the order of the operator via the command interface 60,to bring the coupling towards the target duct until it is presented infront of the target duct in a position for connection.

If the three distances are zero or equal to the parameterized distances,it means that the coupling is located facing the target duct in positionfor connection. The calculator then sends a control instruction to theactuator 30 of the coupling to clamp the coupling to the target duct,and then an instruction to disengage the actuators 27, 28, 29 of thearm, so as to make the movements of the arm free once the coupling hasbeen connected and clamped to the target duct.

Lastly, an indicator light 62 indicates to the operator on the commandinterface that the automatic connection has ended successfully.

An emergency stop button for stopping the automatic connectionprocedure, not shown, is provided on the command interface 60.

In a variant, not shown, other indicators are provided on the commandinterface to signal to the operator various malfunctions or problems inthe automatic connection process.

According to an embodiment not represented, the means for providinginformation on positioning of the coupling is adapted to cooperatedirectly with a means for providing information on positioning of thebase disposed on the base or on a member that is fixed relative theretoto provide, on the basis of the information on positioning of the base,information on relative positioning of the coupling directly relative tothe base. This may, for example, be the same GPS box 33 cooperating withanother GPS box disposed on the base. Alternatively, if the base isfixed to a quay, the means for providing information on positioning ofthe coupling is adapted to provide information on absolute positioningof the coupling in space, for example via a GPS box and, with the basehaving a position fixed in space, the calculator is adapted tocalculate, on the basis of the GPS coordinates of the fixed base and theGPS coordinates of the coupling mobile in space, the relativepositioning of the coupling directly relative to the base. In thisembodiment, the calculator calculates in real time information onpositioning of the coupling relative to the base according to themovements of the coupling and the information provided by the means forproviding information on positioning of the coupling. The calculator isparameterized with data defining at least one authorized zone forpositioning of the coupling and is adapted to verify in real timewhether the coupling is in the authorized zone. In the opposite case,the calculator is adapted to emit an alarm when the coupling leaves thecorresponding authorized zone. Advantageously, according to a variant,the calculating means are adapted to stop the command for automaticconnection of the coupling when such an alarm is emitted.Advantageously, the fact of providing such authorized zones or workingzones makes it possible to avoid a risk of damage to the system inparticular by rupture or interference when the coupling is moved too farfrom the base during extension or rotation.

In this case, the calculator is programmable so as to define workingzones and/or forbidden zones which may be parameterized by the operatoraccording to each loading or unloading operation of fluid products. Thismakes it possible, for example, to adapt the automatic connectionprocedure to different ships which may have different possiblecollisions zones.

Light or sound emitting indicators are provided to warn the operator ofthe crossing of an authorized zone boundary.

In an embodiment that is not represented, several marine loading systemsare connected to the same calculator 40, and a selector is provided atthe command interface to selectively control the connection of one orother of the loading systems linked to the calculator. Working zonescorresponding to the neighboring loading system are programmed so as toavoid collisions between the different loading systems.

In an alternative embodiment not represented, the three degrees ofrotational freedom of the coupling at its end relative to the end of theouter tube are controlled by actuators, for example hydraulic motors orjacks. The device is provided with means for providing information onangular orientation of the coupling, and means for providing informationon angular orientation of the target duct, for example pendulum sensors.Suitable calculating means are provided to calculate, according to theinformation provided by the means for providing information on angularorientation of the coupling and of the target duct, control instructionsgiven to the actuators in order for the angular orientation of thecoupling, in position for connection, to be substantially the same asthe angular orientation of the target duct. Thus, the connection is mademore precise and more reliable in that, on connection, the target ductand the coupling are aligned. This makes it possible in particular toreduce the risks of damage to the seals between the coupling and thetarget duct.

In all cases, when the connection has been made, that is to say when thecoupling has been clamped onto the target duct, the calculator sends adisengage instruction to the actuators so as to make the movements ofthe system free in order to enable the coupling to freely follow themovements of the target duct.

FIG. 4 is a diagrammatic view in perspective of another embodiment of aloading arm equipped with a control device according to the invention,in which the means for providing information on positioning of thecoupling is a camera mounted on the coupling. The representation of thecoupling has been simplified for reasons of clarity.

A target 71 is disposed on the target duct 35. The camera is designed tofocus on the target and provide the calculator with an image of thetarget. On the basis of that image, the calculator is adapted tocalculate the relative positioning of the coupling relative to thetarget duct.

To that end, the calculator is provided with an algorithm for processingthe image and for shape recognition in order to determine the distanceand the angle so as to deduce therefrom the relative positioning of thecoupling relative to the target duct. For the calculation of thedistance, the algorithm uses the principle whereby the greater thedistance between the coupling and the target duct, the smaller the imageof the target, and for the calculation of the angle, the principlewhereby, for a circular target, when the coupling is along the axis ofthe target duct, the image of the target is circular, and when thecoupling is axially offset relative to the target duct, the image of thetarget is elliptical.

In another variant, several cameras are disposed to focus on the sametarget and provide several images to the calculator, the latter beingadapted to process all these images to calculate the relativepositioning of the coupling relative to the target duct.

In another embodiment, a camera is mounted on a motorized support,itself controlled by calculating means to pivot in order to becontinuously oriented towards the target and enabling the angularorientation of the camera relative to the axis of the coupling to beknown at any time, the calculating means being adapted to process thisangular orientation information and the image sent by the camera tocontrol the movement of the coupling to a position for connection.

Preferably, for reasons of performance, the target is a reflectivesighting device.

According to an advantageous variant not illustrated, the target may beomitted, and the camera designed so as to take the free end of thetarget duct itself as a target. This embodiment makes it possible inparticular to dispense with having a sighting device or target on thetarget duct. Thus, for example, if the target duct is on a boat, it willbe possible for the device to adapt to all boats of which the ducts arecompatible with the coupling, whether they are equipped with a target ornot.

Apart from the differences described above, structurally, andfunctionally, this embodiment is the same as the embodiment of FIGS. 1to 3, and it will not therefore be described in more detail here.

According to another embodiment not illustrated, the camera may bedisposed on the target duct or on the bridge of a boat so as to be fixedor motorized relative to the bridge of the boat and be oriented toprovide the calculator with an image of the coupling, so as to enablethe calculator to calculate using the same principle of the relativepositioning of the coupling relative to the target duct.

FIG. 5 is a diagrammatic view in perspective of another embodiment of aloading arm equipped with a control device according to the invention,in which the means for providing information on positioning of thecoupling is a tensioned cord between the target duct and the coupling.

At one of its ends, the cord 75 has means for fastening to the targetduct. The other end of the cord is attached to the drum of a reel 72,itself mounted on the coupling. The reel comprises an incremental sensor73 making it possible to determine the length of cord unwound, thisinformation being sent to the calculator which deduces therefrom thedistance between the coupling and the target duct.

Furthermore, an angle sensor 74 of the cord is provided for the cord 75,in order to determine an inclination of the cord relative to at leasttwo reference angles.

In this way, it is possible to determine the relative positioning of thecoupling relative to the target duct on the basis of the two referenceangles and the distance of the unwound cord. The angle sensor is forexample a sensor using an inclinometer or a laser to determine theinclination of the cord relative to said at least two reference angles.

As a variant, the device is provided with a plurality of reels of whichthe cords are attached at separate places, such that on the basis solelyof the information on the unwound distances provided by the reelsensors, the calculator calculates the angles and the distance for therelative positioning of the coupling relative to the target duct.

On putting it in place, the cord is first of all fastened to aprojectile which is thrown by means known to the person skilled in theart from the quay to the ship, or from the ship to another ship. Anoperator then fastens the free end of the cord to a place provided onthe target duct. The operator may then launch the procedure forautomatic connection using the same principle as in the embodiment ofFIGS. 1 to 3.

According to a variant not illustrated, the reel is provided with a cordrupture detector to suspend the connection procedure in case of ruptureof the cord and to trigger a procedure for retraction of the arm. Acorresponding warning is then communicated to the operator via thecommand interface, for example by an indicator light indicating thebreakage of the cord.

FIGS. 6a and 6b are diagrammatic views in perspective of anotherembodiment of the loading arm equipped with a control device accordingto the invention, in which two different means of providing informationon positioning of the coupling are used. One of the means makes itpossible to determine the positioning of the coupling with greaterprecision than the other. The calculator 40 is adapted to use the meansfor positioning of the coupling having the least precision to perform arough approach for the purpose of the connection of the coupling to thetarget duct and then, when the distance between the coupling and thetarget duct becomes less than a predefined distance, the calculator usesthe coupling positioning information means having the greatest precisionto perform the final phase of the approach for the purpose of presentingthe coupling in front of the target duct in a position for connection.In practice, in a first phase the calculator uses positioninginformation from the GPS boxes 33 and 34 according to the same principleas described earlier, and in a second phase the calculator usespositioning information from a laser device comprising a laser emitter77, and a target 76, the device being adapted to determine, by virtue ofa laser beam 78, the relative positioning of the coupling relative tothe target duct during the final phase of the approach aiming to presentthe coupling in front of the target duct in a position for connection.Thus, advantageously, the device takes advantage of the features of thedifferent means for providing information on positioning of the couplingand of the target duct by matching their degrees of precision with thedistance remaining to reach a position for connection. The precision ofthe connection is optimized thereby. As a variant, the laser device isreplaced by an infra-red device.

Generally, in a variant that is not illustrated which applies to all theembodiments described above, several arms are controlled by the samecalculator. A selector provided on the command interface enables aplurality of loading arms, linked to the same calculator, to becontrolled using the same principle and with the same command interface.

In another general variant that is not illustrated, the commandinterface is a remote control unit provided with a transmitter forwireless communication with a receiver linked to the calculator in theelectrical control cabinet. The transmitter and receiver communicate byradio waves. As a variant, the transmitter and the receiver communicateby optical waves, for example infrared waves.

In a variant not illustrated, at least one of the actuators of theloading arm is a proportional control actuator. In this variant, thecalculator is adapted to control the proportional control actuators.Advantageously, the use of a proportional control actuator makes itpossible to have movement of the coupling that is direct andrectilinear, and thus shorter and faster. This enables the time for theautomatic connection procedure to be reduced.

Numerous other variants are possible according to circumstances, and inthis connection it is to be noted that that the invention is not limitedto the examples represented and described.

1. A marine loading arm comprising: at least one fluid transfer linehaving a fixed line end fixed to a base and a moveable line end providedwith a coupling adapted for connection to a target duct, the couplinghaving at least three degrees of freedom relative to the base; and acontrol device for controlling the movement and positioning of thecoupling, the control device comprising at least three actuators, eachof which is an electric motor which controls movement of the coupling ina corresponding degree of freedom and is provided at an articulation ofthe loading arm that provides the corresponding degree of freedom; thecontrol device further comprising a first global positioning systemdevice positioned on or adjacent the coupling for providing informationon the absolute positioning of the coupling in space.
 2. The marineloading arm according to claim 1, wherein the control device furthercomprises calculating means for (a) calculating the positioning of thecoupling relative to the target duct on the basis of information on theabsolute positioning of the target duct in space and the information onthe absolute positioning of the coupling in space, (b) calculatingcontrol instructions for each of the actuators which will result inmovement of the coupling toward the target duct, (c) applying saidcontrol instructions to the actuators to bring the coupling toward thetarget duct, and (d) repeating steps (a)-(c) as necessary until thecoupling is located in a position for connection to the target duct. 3.The marine loading arm according to claim 1, wherein the coupling isarticulated with three degrees of rotational freedom relative to themovable end of the fluid transfer line, and wherein the control devicefurther comprises: at least one additional actuator for controllingmovement of the coupling in at least one of the three rotational degreesof freedom, the at least one additional actuator comprising an electricmotor; means for providing information on the angular orientation of thecoupling; and means for providing information on the angular orientationof the target duct; wherein the calculating means is adapted tocalculate, on the basis of the information on the angular orientation ofthe coupling and on the angular orientation of the target duct, controlinstructions for the at least one additional actuator in order to makethe angular orientation of the coupling in the position for connectionsubstantially the same as the angular orientation of the target duct. 4.The marine loading arm according to claim 1, further comprising aclamping actuator for enabling the coupling to be clamped and unclamped,wherein once the coupling is in the position for connection, thecalculating means applies a control instruction to said clampingactuator to clamp the coupling onto the target duct.
 5. The marineloading arm according to claim 4, wherein once the coupling has beenclamped onto the target duct, the calculating means applies aninstruction to disengage the actuators.
 6. The marine loading armaccording to claim 1, further comprising a second global positioningsystem device positioned on or adjacent the target duct for providingthe information on the absolute positioning of the target duct in space.7. The marine loading arm according to claim 6, wherein the first andsecond global positioning system devices comprise means forcommunicating with each other and means for calculating and providinginformation on the positioning of the coupling relative to the targetduct.
 8. A marine loading arm comprising: at least one fluid transferline having a fixed line end fixed to a base and a moveable line endprovided with a coupling adapted for connection to a target duct, thecoupling having at least three degrees of freedom relative to the base;and a control device for controlling the movement and positioning of thecoupling, the control device comprising at least three actuators, eachof which is an electric motor which controls movement of the coupling ina corresponding degree of freedom and is provided at an articulation ofthe loading arm that provides the corresponding degree of freedom; thecontrol device further comprising means positioned on or adjacent atleast one of the coupling and the target duct for providing informationon the positioning of the coupling; wherein the coupling positioninginformation means includes an optical device which is fixed relative toone of the coupling and the target duct and is adapted to emit aluminous beam towards the other of the coupling and the target duct,detect the reflected beam, measure the travel time of the beam anddeduce therefrom the positioning of the coupling relative to the targetduct.
 9. The marine loading arm according to claim 8, wherein thecontrol device further comprises calculating means for (a) calculatingthe positioning of the coupling relative to the target duct on the basisof the information on the positioning of the coupling, (b) calculatingcontrol instructions for each of the actuators which will result inmovement of the coupling toward the target duct, (c) applying saidcontrol instructions to the actuators to bring the coupling toward thetarget duct, and (d) repeating steps (a)-(c) as necessary until thecoupling is located in a position for connection to the target duct. 10.A marine loading arm comprising: at least one fluid transfer line havinga fixed line end fixed to a base and a moveable line end provided with acoupling adapted for connection to a target duct, the coupling having atleast three degrees of freedom relative to the base; and a controldevice for controlling the movement and positioning of the coupling, thecontrol device comprising at least three actuators, each of which is anelectric motor which controls movement of the coupling in acorresponding degree of freedom and is provided at an articulation ofthe loading arm that provides the corresponding degree of freedom; thecontrol device further comprising a camera which is fixed relative toone of the coupling and the target duct and is adapted to provide animage of the other of the coupling and the target duct or of a targetwhich is fixed relative to the other of the coupling and the targetduct.
 11. The marine loading arm according to claim 10, wherein thecontrol device further comprises calculating means which is adapted to:(a) process the image provided by the camera and calculate therefrom thepositioning of the coupling relative to the target duct, (b) calculatecontrol instructions for each of the actuators which will result inmovement of the coupling toward the target duct, (c) apply said controlinstructions to the actuators to bring the coupling toward the targetduct, and (d) repeat steps (a)-(c) as necessary until the coupling islocated in a position for connection to the target duct.
 12. A marineloading arm comprising: at least one fluid transfer line having a fixedline end fixed to a base and a moveable line end provided with acoupling adapted for connection to a target duct, the coupling having atleast three degrees of freedom relative to the base; and a controldevice for controlling the movement and positioning of the coupling, thecontrol device comprising at least three actuators, each of which is anelectric motor which controls movement of the coupling in acorresponding degree of freedom and is provided at an articulation ofthe loading arm that provides the corresponding degree of freedom; thecontrol device further comprising means positioned on or adjacent atleast one of the coupling and the target duct for providing informationon the positioning of the coupling relative to the target duct; whereinthe means for providing information on the positioning of the couplingrelative to the target duct comprises a cord which is tensioned betweenthe coupling and the target duct using a reel, and at least one of acord angle sensor and an unwound cord length sensor.
 13. The marineloading arm according to claim 12, wherein the control device furthercomprises calculating means for (a) calculating the positioning of thecoupling relative to the target duct on the basis of the information onthe positioning of the coupling relative to the target duct, (b)calculating control instructions for each of the actuators which willresult in movement of the coupling toward the target duct, (c) applyingsaid control instructions to the actuators to bring the coupling towardthe target duct, and (d) repeating steps (a)-(c) as necessary until thecoupling is located in a position for connection to the target duct. 14.The marine loading arm according to claim 1, wherein at least one of theactuators comprises a proportional control actuator.
 15. The marineloading arm according to claim 2, further comprising at least a secondmeans for providing information on the positioning of the coupling, saidsecond means being adapted to determine the positioning of the couplingwith greater precision than the first global positioning device, whereinthe calculating means (41) uses the information on the positioning ofthe coupling from the second means when the distance between thecoupling and the target duct is less than a predefined distance.
 16. Themarine loading arm according to claim 2, further comprising meanspositioned on or adjacent the base for providing information on theabsolute positioning of the base in space, wherein the calculating meansis adapted to calculate in real time from the information on thepositioning of the coupling and the information on the positioning ofthe base, information on the positioning of the coupling relative to thebase, compare the information on the positioning of the couplingrelative to the base to data defining at least one authorizedpositioning zone for the coupling, and trigger a perceptible alarmsignal when the coupling leaves the authorized positioning zone.
 17. Themarine loading arm according to claim 16, wherein the calculating meansis adapted to stop the application of the control instructions to theactuators when the coupling leaves the authorized positioning zone.